What is this?

[Danno]

The wider part, o-ring side, rotates on internal bearings.
Many thanks!!

 

[reemoeMO]

Searching leads me to a Chrome C-Lock Heavy Duty Locking 5/8 inch Hitch Pin. Of course, I may be wrong!

 

[Danno]

Searching leads me to a Chrome C-Lock Heavy Duty Locking 5/8 inch Hitch Pin. Of course, I may be wrong!

Close, but the long attached pointed end doesn't match.

 

[Nukeman7]

It is the ground spike base section for a vertical flutter banner flag pole like you might see at a car dealership.

 

[Danno]

I work at a car dealership.

Makes sense now.

Thanks!!

 

[RDMgr]

It's the main shaft from a turbo encabulator. The aviation models used that knurled speed adjuster.

 

[Boomer]

Can opener for blinker fluid.